1. Field of the Invention
The present invention relates to a zippered bag having a zipper by which a mouth portion to be formed can be opened or closed, and a method for manufacturing such a zippered bag.
2. Description of the Related Art
There have conventionally been known a self-standable pouch or a flat bag with a zipper by which a mouth portion to be formed could be opened or closed. The zipper provided on such a bag is composed of a male track and a female track engageable therewith. The male track and the female track are formed on the inner surfaces of a pair of opposing face members of a main bag body, respectively, so as to face each other and extend in the lateral direction of the main bag body. The zipper substantially extends over the main bag body in the lateral direction so that an opening operation of the zipper causes the main bag body to be opened over the entire region in the lateral direction thereof.
When the bag with the zipper opened is inclined and shaken lightly to hit softly the mouth portion of the bag against the rim of a vessel such as a cup, in order to pour the powdery or granular contents, with which the bag is filled, directly into the vessel, the contents may suddenly be spilled out in an unexpectedly large amount, thus causing inconvenient problems in handling.
In addition, the full length of the zipper is so long to substantially extend over the main bag body in the lateral direction, thus increasing the probability of occurrence of clogging of the female track with the contents. Especially in case where the bag is filed with the fine granular contents, the probability of occurrence of clogging may remarkably increase. The occurrence of clogging of the female track with the contents may make it impossible to keep the zipper in a completely closed state, thus deteriorating a function of maintaining quality of the contents in an appropriate manner.